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Found 69 entries in the Bibliography.
Showing entries from 1 through 50
2022 |
A paper A new method to subtract dayglow for auroral observation of SSUSI in LBH ranges based on the improved AURIC reports a new method to estimate the dayglow intensities in DMSP/SSUSI LBH bands using an improved AURIC model. It is claimed that the new method offers a better alternative than the SSUSI operational algorithm which uses a data based table. The paper showed a few examples and compared them with SSSUI operational results. The comparison indicated that the new method didn t offer any improvement and provided net ... Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: mar YEAR: 2022   DOI: 10.1016/j.jastp.2022.105833 |
Thermospheric density enhancement and limb O 130.4 nm radiance increase during geomagnetic storms We explore a connection between thermospheric density enhancement and increase in thermospheric O 130.4 nm radiance. We observe TIMED/GUVI enhancements in the limb 130.4 nm radiances at ∼400 and ∼520 km on the dayside during four intense geomagnetic storms in 2003 and 2004. The enhancements were well correlated with Dst and CHAMP total neutral density at 400 km which represents O density as O is the dominant species at those altitudes. At the 400 and 520 km altitudes, O 130.4 nm emissions are mostly created by two ... Zhang, Yongliang; Paxton, Larry; Schaefer, R.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: mar YEAR: 2022   DOI: 10.1016/j.jastp.2022.105830 FUV emission; Geomagentic storms; neutral density; thermosphere |
Simultaneous Detection of Signatures of Conjugate Photoelectrons in the Ionosphere and Thermosphere We investigate the impact of conjugate photoelectrons (CPEs) on the topside (∼600 km altitude) ionosphere at low and midlatitudes using measurements of the ion temperature, density, and composition from the first Republic of China satellite during a period of the high to moderate solar activity (March 1999 to June 2004). Elevated ion temperatures and densities are observed in the dark Northern American-Atlantic sector during the December solstice and in the Australian sector during the June solstice. The oxygen ion fractio ... Kil, Hyosub; Paxton, Larry; Schaefer, Robert; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2022   DOI: 10.1029/2021JA030121 airglow; conjugate photoelectron; ion density; ion temperature |
Thermospheric density enhancement and limb O 130.4 nm radiance increase during geomagnetic storms
Zhang, Yongliang; Paxton, Larry; Schaefer, R; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: |
Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: |
Increased Sensitivity FUV Spectrographic Imager
Schaefer, RK; Paxton, LJ; Zhang, Y; Kil, H; Liou, K; Published by: Published on: |
Hemispheric Asymmetry in the Auroral Ionosphere-Thermosphere System
Liou, K; Zhang, Y-L; Paxton, LJ; Kil, H; Schaefer, R; Published by: Published on: |
Revisiting the November 2004 Superstorm: Lessons from the TIMED/GUVI Limb Observation We revisited the November 2004 superstorm by analyzing data from TIMED/GUVI, a FUV spectrograph imager. The GUVI 135.6 nm limb radiances at 520-km tangent altitude are mainly due to the O+ and electron radiative recombination and represent the daytime ionosphere density at the altitude. The 135.6 nm radiances clearly showed a signature of ionospheric equatorial arcs and their variations during the November 2004 magnetic superstorm. When an intense eastward Interplanetary Electric Field (IEF) occurred, the dayside equatorial ... Zhang, Yongliang; Wang, Wenbin; Paxton, Larry; Schaefer, Robert; Huang, Chaosong; Published by: 44th COSPAR Scientific Assembly. Held 16-24 July Published on: |
Thermospheric conditions associated with the loss of 40 Starlink satellites We analyzed far ultraviolet data from Defense Meteorological Satellite Program (DMSP)/Special Sensor Ultraviolet Spectrographic Imager (SSUSI) and Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)/Global Ultraviolet Imager (GUVI) and found significant changes in the thermospheric density and composition during the 3–5 February 2022 storm when 40 Starlink satellites started to re-enter the atmosphere associated with increased neutral drag at an altitude around 210 km. The standard NRLMSISE-00 model predicts ... Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Swartz, William; Published by: Space Weather Published on: YEAR: 2022   DOI: 10.1029/2022SW003168 |
2021 |
Exploring the Upper Atmosphere In this chapter, we describe how we can understand the state of the upper atmosphere (the ionosphere, thermosphere, and aurora) using optical observations and how one produces a global view of the Earth s upper atmosphere from optical remote sensing, especially using far ultraviolet (FUV) wavelengths, to advance our understanding of the near Earth space environment. We examine the choice of optical signatures, the basic science behind the signatures, and the techniques for observations. Examples of the technique as applied t ... Paxton, Larry; Zhang, Yongliang; Kil, Hyosub; Schaefer, Robert; Published by: Published on: YEAR: 2021   DOI: 10.1002/9781119815631.ch23 Earth space environment; far ultraviolet wavelengths; high-latitude regions; optical remote sensing; solar wind; upper atmosphere |
Far Ultraviolet Hyperspectral Imager: NASA's TIMED/GUVI and DMSP SSUSI
Paxton, Larry; Zhang, Yongliang; Schaefer, Robert; Kil, Hyosub; Wolven, Brian; Romeo, Giuseppe; Yonker, Justin; Published by: Published on: |
Signatures of conjugate photoelectrons in the ionosphere and thermosphere
Kil, Hyosub; Paxton, Larry; Schaefer, Robert; Huba, Joseph; Published by: Published on: |
Exploring the Upper Atmosphere: Using Optical Remote Sensing
Paxton, Larry; Zhang, Yongliang; Kil, Hyosub; Schaefer, Robert; Published by: Upper Atmosphere Dynamics and Energetics Published on: |
Ionospheric and thermospheric contributions in TIMED/GUVI O 135.6 nm radiances
Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Journal of Geophysical Research: Space Physics Published on: |
Schaefer, Robert; Paxton, Larry; Zhang, Yongliang; Kil, Hyosub; Romeo, Giuseppe; Wolven, Brian; Yonker, Justin; Published by: Published on: |
2020 |
This study investigates the origin of anomalous far ultraviolet emissions observed at night at the subauroral region by the Special Sensor Ultraviolet Spectrographic Imager on board the Defense Meteorological Satellite System-F16 satellite. The global distribution of the anomalous emission is derived using the measurements of the oxygen atom 130.4-nm emission in 2017. Our results show the extension of the anomalous emission from high latitudes to middle latitudes in the Northern American-Atlantic sector during the Decembe ... Kil, Hyosub; Schaefer, Robert; Paxton, Larry; Jee, Geonhwa; Published by: Geophysical Research Letters Published on: 01/2020 YEAR: 2020   DOI: 10.1029/2019GL086383 conjugate photoelectron; far ultraviolet emission; thermosphere; remote sensing data |
Kil, Hyosub; Schaefer, Robert; Paxton, Larry; Jee, Geonhwa; Published by: Geophysical Research Letters Published on: |
Estimation of solar EUV flux from TIMED/GUVI data
Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: |
A comparison of thermospheric FUV radiance and composition from TIMED, GOLD and ICON
Zhang, Y; Paxton, LJ; Schaefer, RK; Eastes, R; McClintock, WE; Immel, TJ; Published by: Published on: |
2019 |
This paper reports a preliminary result for estimating thermospheric temperature around 155 km from the N2 Lyman-Birge-Hopfield bands observed by TIMED/Global Ultraviolet Imager (GUVI). Atmospheric Ultraviolet Radiance Integrated Code model (Strickland et al., 1999, https://doi.org/10.1016/S0022-4073(98)00098-3) calculations indicate that the intensity ratio in the N2 Lyman-Birge-Hopfield (0,0) and (1,0) bands at 144.5- ... Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Journal of Geophysical Research: Space Physics Published on: 06/2019 YEAR: 2019   DOI: 10.1029/2018JA026379 |
Addressing O2R with the SSUSI Operational Space Sensor: Lessons Learned
Schaefer, Robert; Paxton, Larry; Romeo, Giuseppe; Kil, Hyosub; Wolven, Brian; Zhang, Yongliang; Published by: Published on: |
Storm-time variations in the thermsopheric density, composition and temperature.
Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Published on: |
2018 |
Storm-time variations of atomic nitrogen 149.3 nm emission Net radiances of atomic nitrogen emission line (N-149.3 nm) from the thermosphere are extracted from the FUV spectra observed by TIMED/GUVI on dayside at ... Zhang, Y.; Paxton, L.J.; Morrison, D.; Schaefer, B.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 04/2018 YEAR: 2018   DOI: 10.1016/j.jastp.2018.01.023 |
SSUSI and SSUSI-Lite: Providing space situational awareness and support for over 25 years
Paxton, Larry; Schaefer, Robert; Zhang, Yongliang; Kil, Hyosub; Hicks, John; Published by: Johns Hopkins APL Technical Digest Published on: |
Nightime Ionosphere Climatology as observed by TIMED/GUVI
Schaefer, Robert; Edenbaum, Harris; Published by: Published on: |
2017 |
We present the Volume Emission Rate Tomography (VERT) technique for inverting satellite-based, multisensor limb and nadir measurements of atmospheric ultraviolet emission to create whole-orbit reconstructions of atmospheric volume emission rate. The VERT approach is more general than previous ionospheric tomography methods because it can reconstruct the volume emission rate field irrespective of the particular excitation mechanisms (e.g., radiative recombination, photoelectron impact excitation, and energetic particle pre ... Hei, Matthew; Budzien, Scott; Dymond, Kenneth; Nicholas, Andrew; Paxton, Larry; Schaefer, Robert; Groves, Keith; Published by: Radio Science Published on: 07/2017 YEAR: 2017   DOI: 10.1002/2015RS005887 |
Far ultraviolet instrument technology The far ultraviolet (FUV) spectral range (from about 115 nm to 180 nm) is one of the most useful spectral regions for characterizing the upper atmosphere (thermosphere and ionosphere). The principal advantages are that there are FUV signatures of the major constituents of the upper atmosphere as well as the signatures of the high-latitude energy inputs. Because of the absorption by thermospheric O2, the FUV signatures are seen against a \textquotedblleftblack\textquotedblright background, i.e., one that is not ... Paxton, Larry; Schaefer, Robert; Zhang, Yongliang; Kil, Hyosub; Published by: Journal of Geophysical Research: Space Physics Published on: 01/2017 YEAR: 2017   DOI: 10.1002/jgra.v122.210.1002/2016JA023578 |
A New More Accurate Calibration for TIMED/GUVI
Schaefer, RK; Aiello, J; Wolven, BC; Paxton, LJ; Romeo, G; Zhang, Y; Published by: Published on: |
TIMED/GUVI Observations of Aurora, Ionosphere, Thermosphere and Solar EUV Variations
Zhang, Yongliang; Paxton, Larry; Schaefer, Robert; Published by: Published on: |
Monitoring Geospace Variations Through Remote Sensing III Posters
Zhang, Yongliang; Paxton, Larry; Sibeck, David; Schaefer, Robert; Published by: Published on: |
2016 |
Schaefer, Robert; Paxton, Larry; Zhang, Yongliang; Published by: Published on: |
Validating Local Responses in OVATION Prime-2013 and OVATION-SM with DMSP SSUSI
Mitchell, Elizabeth; Schaefer, Robert; Paxton, Larry; Published by: Published on: |
Structure and Variability in the Ionosphere using DMSP/SSUSI and TIMED/GUVI Data
Bruntz, Robert; Paxton, Larry; Kil, Hyosub; Schaefer, Robert; Zhang, Yongliang; Miller, Ethan; Published by: Published on: |
Selby, Christina; Paxton, LJ; Schaefer, RK; Ogorzalek, B; Romeo, G; Wolven, B; Hsieh, SY; Published by: Published on: |
NASA Timed Guvi and Dmsp Ssusi Observations of the St. Patricks Day Storm of
Paxton, Larry; Zhang, Yongliang; Kil, Hyosub; Mitchell, Elizabeth; Schaefer, Robert; Published by: 41st COSPAR Scientific Assembly Published on: |
2015 |
SSULI/SSUSI UV tomographic images of large-scale plasma structuring
Hei, Matthew; Budzien, Scott; Dymond, Kenneth; Paxton, Larry; Schaefer, Robert; Groves, Keith; Published by: Published on: |
UV Observations of Hemispheric Asymmetry
Schaefer, Robert; Paxton, Larry; Wolven, Brian; Zhang, Yongliang; Romeo, Giuseppe; Published by: Published on: |
GUVI and SSUSI Observations of the St. Patrick's Day Storms
Paxton, Larry; Schaefer, Robert; Zhang, Yongliang; Bust, Gary; Kil, Hyosub; Published by: Published on: |
2014 |
Paxton, LJ; Schaefer, RK; Zhang, Y; Bust, GS; Kil, H; Published by: Published on: |
Gjerloev, Jesper; Schaefer, Robert; Paxton, Larry; Zhang, Yongliang; Published by: Published on: |
Ionospheric Data Assimilation from a Data Provider's Perspective
Schaefer, Robert; Paxton, Larry; Bust, G; Zhang, Yongliang; Romeo, Giuseppe; Comberiate, Joseph; Gelinas, Lynette; Published by: Published on: |
EMIC Wave Induced Radiation Belt Losses and Proton Aurora
Erlandson, Robert; Paxton, Larry; Zhang, Yongliang; Schaefer, Robert; Published by: Published on: |
Specification of Auroral Ionospheric Conductances Using SSUSI and GUVI UV Imagery
Paxton, Larry; Zhang, Yongliang; Schaefer, Robert; Weiss, Michele; Miller, Ethan; Published by: Published on: |
Operational Space Weather Needs-Perspectives from SEASONS 2014
Comberiate, Joseph; Kelly, MA; Paxton, Larry; Schaefer, Robert; Bust, Gary; Sotirelis, Thomas; Fox, Nicola; Published by: Published on: |
Establishing the connection between crowd-sourced data and decision makers
Paxton, Larry; Swartz, W; Strong, Shadrian; Nix, MG; Schaefer, Robert; Weiss, Michele; Published by: Published on: |
Schaefer, Robert; Paxton, Larry; Romeo, Giuseppe; Wolven, Brian; Zhang, Yongliang; Comberiate, Joseph; Published by: Published on: |
2013 |
Multi-Instrument Observations at High Latitudes
Miller, E; Paxton, L; Schaefer, RK; Weiss, M; Wolven, BC; Zhang, Y; Published by: Published on: |
Observing the mid-and low-latitude ionosphere-global UV remote sensing
Paxton, LJ; Kil, H; Miller, ES; Comberiate, J; Schaefer, RK; Zhang, Y; Team, GUVI; , others; Published by: Published on: |
Schaefer, RK; Wolven, BC; Paxton, L; Romeo, G; Selby, C; Hsieh, SW; Published by: Published on: |
UV Remote Sensing Data Products-Turning Data Into Knowledge
Weiss, M; Paxton, L; Schaefer, RK; Comberiate, J; Hsieh, SW; Romeo, G; Wolven, BC; Zhang, Y; Published by: Published on: |
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